4-2 Assessment

1. What is the difference between a biotic factor and an
abiotic factor?
• Biotic = living,
abiotic = non-living.
• Biotic: animals,
plants, people, etc.
• Abiotic: weather,
temperature,
rainfall, soil, etc.
2. Name three types of community interactions that can
affect an ecosystem.
• Community = All
living things in an
area.
• Competition:
organisms of
same or diff.
species compete
for resources.
• Predation: one
animal hunts &
feeds on another.
Who is competing? Who are the predators?
2. Name three types of community interactions that can
affect an ecosystem.
Symbiosis: two species living
closely together.
3. What is the difference between primary succession and
secondary succession?
Primary succession = changes in ecosystem where no
plants or animals to start with.
3. What is the difference between primary succession and
secondary succession?
Secondary = changes after an existing community is
disturbed, e.g. by forest fire, human impact.
4. How is an organism’s niche determined?
• Niche = an organism’s role in an ecosystem, what it does.
• Determined by what it eats, who eats it, where it lives (habitat).
4. How is an organism’s niche determined?
• Niche = an organism’s role in an ecosystem, what it does.
• Determined by what it eats, who eats it, where it lives.
5. How are the three types of symbiotic relationships different?
Similar? • Mutualism = both species benefit, e.g. flowers and bees.
• Commensalism = one benefits; other is not helped or hurt,
e.g. whales and barnacles.
• Parasitism = one lives on or in the other and hurts it, e.g.
tapeworms and cats.
All involve two
species of
organisms
living close
together.
6. Summarize the role of organisms, including microorganisms, in
maintaining the equilibrium of a marine ecosystem while a dead
whale decays on the ocean floor.
1. Sharks, hagfish, amphipods, etc. eat decaying flesh.
2. Crabs, snails, worms eat leftovers and nutrients in sediment.
6. Summarize the role of organisms, including microorganisms, in
maintaining the equilibrium of a marine ecosystem while a dead
whale decays on the ocean floor.
3. Bacteria decompose bones. Mussels, clams, snails,
crabs, worms feed on bacteria.
Equilibrium = Everything in balance
Equilibrium = Everything in balance
What happens if there are too many frogs….?
Equilibrium = Everything in balance
What happens if there are too many grasshoppers….?
Equilibrium = Everything in balance
Equilibrium = Everything in balance